Field of the Invention
The invention of the instant application relates to a copy or web-guiding cylinder having a guiding device for extensible operating elements, such as folding knives or tucker blades, pins, or the like.
U.S. Pat. No. 2,991,702 discloses a folding jaw cylinder which cooperates with an opposed folding cylinder. Two folding jaws, respectively, disposed on a prestressable shaft, are provided in a recess formed on the circumference of the folding jaw cylinder, and are opened to receive a spine of a fold which is thrust by the folding knife into the free space between the folding jaws. The extent of prestressing of the torsion bars for the folding jaw may be limited by a torsion coupling. If a set or adjusted load is exceeded, an overstraining or overloading of the components is prevented by releasing the torsion coupling.
The published German Patent Document DE 42 15 911 A1 shows a folding jaw cylinder for a printing press. A folding jaw is rotatably disposed on the cylinder and includes a stop, a rotary body connectable to the cylinder and having an angular position adjustable relative to the cylinder, and a gear transmission for setting an operating space between the folding jaw and the stop by adjusting the angular position between the cylinder and the rotary body. The stop is movably disposed on the cylinder and, when the angular position between the cylinder and the rotary body is adjusted, the stop is adjusted relative to the cylinder by adjusting means applied to the rotary body and secured to the stop. The folding knife cooperating with the corresponding folding jaws is accommodated in quite a large recess, as viewed in the circumferential direction.
The published German Patent Document DE 29 36 768 C2 discloses an adjustable folding device or folder for rotary printing presses. On a collecting or gathering cylinder shown in this reference, the folding knives are received in folding knife cassettes on the circumference of the cylinder.
The published German Patent Document DE 690 08 007 T2 shows a folding and cutting apparatus for a web of printing paper. In this configuration, mutually opposing folding knives are mounted on a folding knife cylinder and are secured in recesses. A recess formed on the circumference of the folding knife cylinder and extending circumferentially on both sides of the edge of the folding knife impairs the accuracy or precision of the copy transfer from the folding knife cylinder to the folding jaw cylinder in the folding apparatus.
It has been found that the recess extending in the circumferential direction on either side of the folding knives on the folding knife cylinder has the effect, at relatively high production speeds, of causing the copy to be thrust by the folding knife into an opposing just-opened folding jaw to enter the recess surrounding the folding knife and become creased. The impact of the folding knife as it moves outwardly on the copy creates a pulse which is propagated over the copy in the form of an undulating or wavelike discontinuity or disruption on both sides of the impact location of the outwardly moving folding knife, causing temporary deformation of the copy to be transferred.